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Accueil > Recherche > (GRIFON) GRoupe Interactions FOndamentales et nature du Neutrino

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Fundamental interactions

The group activities are mainly motivated by the search of "new physics" (beyond the Standard Model), through high precision and high sensitivity experiments at "low energy". These experiments are complementary to high energy experiments performed at large scale colliders such as the LHC.

This research activity comprises six projects within three main topics :




-The nEDM experiment searchs for new sources of CP violation via the measurement of a non zero electric dipole moment of the neuron (at PSI, Switzerland).

The observable Universe is mainly made of matter with only tiny tracks of antimatter. Such a dominance of the matter over the antimatter is not understood and the standard model of particles physics is not able to account for it yet.
In 1967, A. Sakharov showed that three requirements are needed to account for the matter emerging in the early Universe : thermal non equilibrium, C and CP violations and non-conservation of the baryon number. The measurement of electric dipole moment (EDM) of elementary particles or composite system (electron, neutron, Hg and so on …) allows to chase one of them : the CP symmetry breaking. This violation has been discovered in the K and B mesons, but its amount is so tiny that it cannot explain the matter-antimatter asymmetry observed in the Universe. On the other hand, any measurement of a non-null EDM shows a violation of this symmetry. The EDMs hunt begun in the fifties and, up to now, no team has been able to discover an EDM : all measurements are compatible with zero.
In this context, the international collaboration nEDM, composed of 12 institutions, is measuring the neutron EDM at the Paul Scherrer Institute (PSI) in Switzerland. The Laboratoire de Physique Corpusculaire de Caen (LPC) is one of the collaboration founder. The experiment is carried out with the ultra-cold neutrons source at PSI which provides the most intense beam of Ultra Cold Neutrons worldwide. The experiment is running since 2012 with a constant improvement of the nEDM apparatus. As a result, in 2015, the daily statistical sensitivity was large enough to expect a new worldwide limit on the neutron EDM in 2016. The systematic errors are under control and a factor 10 below the statistical error.
In the collaboration, the LPC is in charge of the neutron detection, the analysis of their polarisation and the achievement of the coils required to produce the magnetic field used for the measurement. It is also deeply involved in the data analysis altogether with the LPSC Grenoble and the CSNSM laboratories.
A new spectrometer is currently under construction. It should be ready to operate in 2019 and will be able to search for neutron EDM in sensibilities domains ( 10-27 never explored yet.




- LPCTrap : tests of the Standard Model in nuclear beta decay via the precise measurement of beta-neutrino angular correlation. En savoir plus...
- Developments for SPIRAL2 : High intensity beam cooler(SHIRAC), Laser spectroscopy and low energy beam production with S3 exotic ions(REGLIS3). En savoir plus...
- LPC-MOT et ion-molecule collisions (activities in atomic physics). En savoir plus...


Neutrino physics

- NEMO-3/SuperNEMO (au LSM) : search for neutrinoless double beta decay (Majorana neutrinos). En savoir plus...
- SoLiD : Search for a sterile neutrino in short base oscillation measurements close to a nuclear reactor(BR2, Mol, Belgium). En savoir plus...

These research activities are performed within international collaborations where the LPC Caen plays a major role. The experimental setups are installed at large research facilities such as the Institut Laue-Langevin (ILL, France), the Paul Scherrer Institute (PSI, Switzerland), the GANIL/SPIRAL2 (Caen, france), the Laboratoire Souterrain de Modane (LSM, France/Italy), the CENPA (Seattle, USA), CERN/ISOLDE (France/Switzerland), and the research nuclar reactor BR2 (SCK-CEN, Belgium).